The invention relates to method and apparatus for the combustion of pulverized coal in general, and more particularly for coals having a low flammability such as semi-bituminous coals and anthracite.
Low flammability is due in the first place to a lack of volatile gases which are inherent to a particular kind of coal or which result from treatment of the coal. This may be desirable in order to be able to stack the coal without risk of explosion caused by the accumulation of gas and air mixture in the closed containers. However, the low flammability of such coals make it difficult to start the combustion process in a burner. For start-up with coal dusts of this kind, it has been necessary in the past to add propane gas and light oil as additional fuel. In such instances, coal dust amounts to 70% while 26% of light oil is added with 4% of propane gas. This is not a good economical proposition, especially because of the propane gas.
An object of the present invention is a method and an apparatus for an effective combustion of pulverized coal of poor flammability.